The Emsian is one of three in the Early Devonian Epoch. It lasted from 410.62 ±1.95 million years ago to 393.47 ±0.99 million years ago.[Cohen, K.M., Finney, S.C., Gibbard, P.L. & Fan, J.-X. (2013; updated) The ICS International Chronostratigraphic Chart. Episodes 36: 199–204.] It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after the Ems river in Germany.
In North America the Emsian Stage is represented by Sawkill or Sawkillian time.
Biological events
During this period, earliest known
Agoniatitida Ammonoidea fossils began appearing within this stage after first appearing in previous stage and began to evolutionarily radiate within this stage, in which a new ammonoid order
Goniatite rises in the end of Zlichovian stage (Siberian representation; corresponds to early Eifelian and after the end of Early Devonian, before 391.9
Annum).
Later agoniatitid ammonoids would die out in the
Taghanic event in the upper middle
Givetian. Goniatite ammonoids would give rise to further ammonoid orders, thus starting ammonoid dominance of marine fossils in further periods until their end at the Cretaceous-Paleogene mass extinction event.
